High-frequency relay



1952 I P: M. GXTOULON 2,581,984

HIGH-FREQUENCY RELAY Filed March 18, 1950 CONTROL VOLTAGE 140 18 SYNC.

INVENTOR PIERRE MARIE GABRIEL TOULON ATTORNEY Patented Jan. 8, 1952 2,581,984 HIGHeFR EQUENCY RELAY Pierre Marie Gabriel Toulon, New York, N. Y., as-

signor to-P'roducts' & Licensing Corporation, New York, N. Y.,' a corporation of Delaware Application March 18, 1950, Serial No. 150,513

' In France March 23, 1949 13 Claims. (01. 315 -326) The present invention relates generally to controllable circuit makers and breakers, comprising air gap devices having no movable parts, and particularly to devices of this character comprising three or more electrodes in series, acrosswhich is impressed a high frequency voltage, the high frequency voltage dividing between each pair of the electrodes, and when so divided having insufficient magnitude to cause break-down-of the air gaps between any two of the electrodes, and wherein an auxiliary voltage is applied between one pair of the electrodes, which, when of sufficient magnitude, effects break-down of the-gap between that pair, and thereby of the gaps between all the electrodes.

The present invention is based on the ionizing properties of air existing between electrodes across which is impressed a high intensity high frequency field. If the voltage applied to the electrodes is insufficient to break down the air,

by effecting ionization thereof to a sufiicient ex-,

tent, only very small currents flow between the electrodes. The point at which the voltage applied to the electrodes exceeds that required to produce intense ionization in the gap therebetween, and therefore a break-down of thegap and flow of heavy current therein, is a critical point, and may be surpassed by superposing on the high frequency voltage a static D .C.-voltage of suitable magnitude.

In accordance with a preferred embodiment of the present invention three electrodes-establishing two air gaps in series, are provided, and a high frequency voltage of considerable magnitude is impressed across the two air gaps in series. The physical character of the electrodes 'may preferably be such that equal capacitance exists between the first. and second, and' between .the

second and third electrodes. In this event, the total high frequency voltage impressed is divided equally as between the first and second, and the second and third electrodesand the magnitude of the high frequency voltage is so selected that ionization and break-down of the gaps does not occur. A D,-C. control voltage is then impressed between two of the electrodes, say the second and third, superposed on the high frequency voltage existing across these electrodes. By controlling the magnitude of the D.-C. voltage impressed across the latter electrodes ionization may be caused or prevented, substantially without D.-C. current flow, and when caused effects essentially a short circuit between the latter electrodes, so that the entire high frequency voltage appears across the remaining two electrodes. When the I entire high frequency voltage appears across the remaining two electrodes the latter electrodes break-down, and the circuit, comprising both gaps in series across the high frequency voltage, is closed. An appropriate load may be connected in series with the high frequency circuit for energization when the circuit is closed.

It is accordingly a broad object of the present invention to provide an extremely sensitive relay, having no moving parts, which may be controlled in response to extremely small control currents, of the order of 10* to 10- amperes, capable when energized of carrying heavy currents, of the order of one ampere, or greater, of extremely small cost, and of small physical dimensions.

It is a further object of the present invention to provide a system of circuit making and breaking, of the character above described, in a system i of multi-element large screen television reception, wherein each element of the screen comprises a load device for the circuit maker and breaker. I

The above and still further features, objects and advantages of the invention will become apparent upon consideration of the following detailed description of various embodiments there of, especially when taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a schematic circuit diagram of an embodiment of the invention;

Figure 2 is a circuit diagram, partly in functional block and partly schematic, of a television system of the multi-element large screen type, showing the application of the present invention to the control of one element of the screen; and,

Figure 3 is a schematic circuit diagram of a modification of the system of Figure 1.

Referring now more specifically to the drawings the terminals I represent a source of high frequency voltage of stable amplitude, provided by a generator, indicated generally by the reference numeral 2. The voltage appearing across the terminals I is applied in series with a load device 3, which is illustrated as a lamp, but which may be of any desired character, without departing from the spirit of the present invention. In series with the terminals l and with the load device 3 are three electrodes connected in series, and identified by the reference numerals 4, 5 and 6. The physical structure of the electrodes 4, 5 and 6 may be such thatthe capacitance existing between electrodes 4 and 5 is equal to the capacitance existing between the electrodes 5 and 6. Accordingly, the high frequency voltage provided by the terminals l divides equally, as between electrodes 4, and 5; 6. The voltage is so selected as to be just inadequate for ionizing the air gap between any pair of electrodes, or for causing the break-down of the air gaps. Accordingly, electrodes 4, 5 and 6, in series, represent normally an open circuit.

Connected to the center electrode 5 is a first resistance 1, which may comprise a Bakelite rod as its physical embodiment. In series with the resistance 1 is a further similar resistance 8, which similarly may, in its physical embodiment comprise a Bakelite rod, resistance rods 1 and 8 serving as a support for an anode '9. It .will be realized that the physical character of the resistances l and 8 is such that almost complete electrical isolation exists between electrode 5 and anode 9, but this isolation is not absolutely complete, so that, electrically there exists between the anode 9 and electrode 5 an extremely high resistance. Connected between the junction of resistances I and 8 and the electrode 6 is a condenser. I0. Connected between the anode 9 and electrode 6 is a high resistance II shunted by a further condenser I2. Associated with the anode 9 is a control electrode I3 in the form of an annulus, a grounded electrode I4 in the form of a further annulus, and a pointed cathode electrode I5, the pointed cathode electrode I5, the openings of the annular electrodes I3 and I4, and the anode 9, being co-axial. The electrode I4 may be grounded and a source of negative voltage may be supplied, identified by the reference numeral I6, .for maintaining the pointed electrode I5 highly negative with respect to the grounded electrode -I4, this voltage being of the order of 6000 volts. A source of positive voltag with respect to ground, identified by the reference numeral I'I, may be connected directly to electrode 6, and accordingly via resistance I I to anode 9. The functions of the condensers I I3 and I2 in the circuit is for A.-C. by-pass. The function of the resistance II is to act as aload resistance for the device comprising anode 9 and electrodes I3, I4 and I5, the latter device representing a gaseous conduction device, which is grid controlled in eifect, and which operates in air. Impressed between the electrode 14 and the electrode I5, the latter acting as a control electrode, is a source of control voltage I 8, which applies periodic voltages, as I9, to the control electrode I3.

In operation the high voltage existing between the pointed electrode 55 and the grounded electrode I4 results in a permanent discharge between these electrodes, negatively ionized particles traveling toward the grounded electrode I4. Since the electrode I4 is of annular conformation, having an aperture aligned with the pointed electrode I5, certain of the ionized particles traveling toward the electrode I4 pass through the aperture, and tend tobe collected by the positively polarized anode 9. This tendency is counteracted by the control electrode I-3, when the latter is negative in potential, or approximately at ground potential, and is assisted by the control electrode l3 when the latter becomes positive with respect to ground. When suitable voltages are applied to the control electrode I3 by the source of control voltage I8, these control voltages being positively going, as indicated at I9, current flows to the anode 9, and a circuit being thus completed through the resistance II, voltage changes occur in that resistance. The voltagechanges existing across theresistance II are imparted to the electrodes 5, 6, although cur- H dehs'er'2'8 and an'inducta'nce 29 in parallel.

rent flow between these electrodes is substantially zero, by reason of the fact that the electrodes are in series with the extremely high resistances I and 8. At the same time the super-position of a D.-C. voltage between electrodes 5 and 6, corresponding with the voltage which appears intermittently across high resistance "I'I, results in an unbalance of the electrical forces existing between the pairs of electrodes 4, 5 and 5, 6. Otherwise envisaged, the high frequency voltage existingbetw'een electrodes 5, 6 has superposed thereon a D.-C. voltage, and the total voltage then existing is sufficient to initiate break-down of the gap between electrodes 5, 6. When the gap between electrodes 5 and 6 is broken down the total high frequency voltage applied at terminals I exists across electrodes 4, 5 alone and is sufficient to break-down the latter, so that the circuit from one of terminals I, to the other, is completed through the loaddevice 3, and through the gaps 4, 5, 6. A condenser C is provided in series with load device 3 .as a current limiting device, anda D.-C. blocking device.

In order to break the high frequency circuit completedthrough gaps 4, 5 and 5, a switch '25 is provided, which for the sake of simplicity is illustrated as a manual switch. When the switch 20 is reclosed, if suitable ll-C. voltage does not exist across resistance I], the total high frequency voltage present across terminals I-l again divides as between electrodes 4, 5 and "5, 6 and the high frequency circuit remains closed. At any time that suitable control voltage is applied to electrode I'3 from'eomroi voltage source I8, however, and when switch 20 is closed, 'the circuit again closes.

In operation, the switch '20 may .be i'n'te'rmit t'ntly operated in synchronisin with the application of control pulses fromthe control voltage source T8, or otherwise rapidly opened and closed.

' "It will be realized that it is essential to the success of the circuit makihg-and breaking system of the present invention to provide asource of high frequency voltage at terminals I, which remaix' s constant in amplitude during changes of load current "therefrom. To this end I have devised an amplitude stabilized oscillator 2 com-' prising a triode '21 having an anode '22, a control electrode 23 and a cathode 2'4. A source or positive anode voltage f25"is provided, shown for the sake of convenience as a battery, the positiveterminal of which is connected through a choke 26 to the anode 2'2, and the negative terminal of which is connectedto the "cathode 24. An oscillating circuit 21 is provided, comprising a con- The cathode 24 is f ufther connected via lead 3I to the center point of inductance 29, for the sake of example, while the anode '22 is connected via coupling condenser '32 to one end of the tuned tank oircui tfl'l. The other end of the tank circuit 2'1 is coupled via coupling condenser '33 and lead 34 to control electrode 23. Accordingly the triode 2| oscillate's, its oscillating circuit and interconnections being conventional, and for that reason not explained in detail, and by reason of the high percentage of the inductance coil 29 which is coupled between the cathode 24 and the control electrode'23'the'triode oscillator is strongly driven. 'Biasfor the control electrode 23 is provided across a resistance 34, (shunted bya smoothing condenser '35) one end of which i connected to the negative fterr'r'final of potential source '25, and the other end of whichis connected via a chokec'oil '36 to the control electrode 23. Normally the total voltage across the resistance 34 is zero, so that the normal bias of the control electrode 23 is zero, or

choke 38 to an adjustable point on voltage source 25,-by means of a variable tap 39. Accordingly,

the cathode of the diode 31 is maintained at a positive D.-C. potential with respect to the anode, and the diode remains non-conductive. There is further impressed, across the diode 31, high frequency voltage deriving from the tank circuit 21, this voltage being applied to the cathode via coupling condenser 40, and to the anode via condenser 35 and resistance 34. So long as the magnitude of the high frequency voltage applied to diode 37 remains less than the bias supplied via tap 39 from the voltage source. 25 the diode remains non-conductive in response to the high frequency voltage. Should the high frequency voltage rise' sufficiently to overcome the bias, on the other hand, current will flow, which will be rectified and appear as a D.-C. voltage across resistance 34. When this occurs the bias on triode 2| changes, becoming more negative, which reduce the high frequency voltage. It will be evident then that the triode- 2| and its associated oscillating circuits will provide high frequency voltage at an amplitude just suiiicient to cause some current now through diode 31, and that thereafter any tendency of the amplitude of the output of the triode 2| to increase will be counteracted by a change of bias on the control electrode 23 in a negative direction. Accordingly, the oscillator becomes stabilized in respect to'amplitude of output, and the voltage provided at the terminals is similarly so stabilized.

Reference is now made more particularly to Figure 2 of the accompanying drawings, wherein is' illustrated a portion of a television receiver system, of the type wherein each elemental area of a picture i reproduced in terms of n"ofi conditions of a source of illumination. The system of Figure 2 indicates the application of the system of Figure 1 to such a television system.

In the system of Figure 2 i provided a signal receiver 46 of conventional television signals, comprising video signals representative of the character of a picture, interspersed with synchronizing signals, these latter being both line synchronizing signals and frame synchronizing signals, as'is conventional in the art. The receiver 46 comprises devices for separating the frame signals, the video signals and the line synchronizing signals, and applying these, respectively, to thelines 4|, 42 and 43. The line synchronizing signals provided on the line 43 are applied to a distributor 44, to which are also applied the video signals present on the line 42, it being the function of the distributor 44 to distribute the video signals representative of different horizontal elements of the picture to different ones of the conductors 45, 46, 47, etc. under the control of the line synchronizing signals present on line 43. While I may utilize for this purpose any distributor known in the art, I prefer to utilize a static distributor of the type described in my U. S. Patent #2,471,253. Signals'representative of a given vertical line of the picture may be assumed to be present, then, on the conductor 45. The signals present on the conductor 45 accordingly, are in the form of sucpessivepulseseach pulse representing a horizonm1 element of the picture, the successive ones of the pulses belonging on successively vertically dis-' placed lines of the picture. As many conductors 45, 46, 41 are required as there are horizon-' tal elements in the picture, to wit, about 500. The frame sync signals provided on line 4| are applied to a line pulse generator 48, having output. circuits 49, 56, 5|, etc., one for each vertical line of the picture. In response to each frame sync signal provided by line 4| to line pulse generator 48 a series of spaced pulses is generated, which are applied to successive one of the lines .49, 50, 5|, at line frequency, the lines being enerthe point cathode is successively raised and lowered with respect to ground potential by means of a rotating switch 56, driven by a synchronous motor 51 in synchronism with the frame sync pulses provided over line 4|. The line 56 accordingly is energized during one horizontal line of the picture, and the anode 53 is simultaneously energized, at a proper instant during the time a signal is applied to the control electrode 55, from line 45 (and to similar control electrodes from lines 46, 41 at times following). The point cathode 54 is raised and lowered in potential so that each grid-controlled air operated device becomes conductive during one horizontal line of the picture, and the instant of conductivity of the device is determined by the potential of the control electrode 55 in response to the video signal applied via line 45. The control electrode 55 is energized in response to the video signal while one element of the picture only isbeing generated, that element being represented by the lamp 56. When the air operated gas discharge device comprising anode;53' becomes conductive a voltage drop is communicated to control electrode H of a further air-operated gaseous conduction device, of the character of that illustrated in Figure 1 of the accompanying drawings, and explained in conjunction with that figure. The load device 3 is then operated precisely as in the system of Figure 1.

Referring now more particularly to Figure 3 of the accompanying drawings, there is illustrated a modification of the system of Figure 1, wherein the amplitude regulated oscillator 2 is conventionally illustrated, and supplies amplitude regulated high frequency voltage to the ter minals In this species of the invention three spark gaps 60, 6| and 62 are provided, which are connected in series with the current limiting capacitor C, the switch 20 and high frequency source 2. The physical arrangement of the electrodes 60, 6| and s2 is such the the gaps formed between any pair' of the electrodes does not break down in response to voltage supplied by source 2. Central electrode 6| is connected through extremely high resistances 63, 64 and 65 to a selector arm 66 of a switch 61, the selector arm 66 being movable over a series of contacts, as 68, each of which provides a diiferent potential with respect to ground at the arm 66. This potential is transferred to the central electrode 6|, and should the potential so transferred be such'as to upsetthe balance establishedwith respect to "high frequency voltages as between electrodes 160, :61 and electrodes 181, 62, aabreak down of one of the gaps occurs. When one of the gaps breaks down the remaining gap is subjected to the entire voltage of the generator :2 and it too breaks down, establishing a temporary short circuit through the gaps. In series with gap 60 is a spark coil 69, which generates :an extremely high voltage'at'the instant when current passes through the gaps. Adjacent to the electrode 69 is .a further electrode 10, so arranged "with vrespect to :electrodes at and 6.1 that the electrodes 6'0, 61 and 1c occupy the corners of a triangle. The electrode 10 is connected in series with a load lamp 3, and a source of high positive potential H, to ground. Accordingly, when an extremely high voltage-exists across coil -:69 the voltage in the gap between electrodes 60 :and ID, which in response to high voltage supply '12 remains unionized, breaks down, and current flows. As soon as current flows an essentially short circuit exists between electrodes 60 and 10, and the full voltage of battery 12 becomes effective to cause current now in the lamp '3.

A fundamental distinction as between the systems of Figures 1 and 3 is pointed out, that in the system of Figure 1 the electrodes 4, 5, 6, with their associated circuits, are utilized to close only a circuit in series with the electrodes, while "in the system of Figure 3 these electrodes are utilized to close their associated circuits, and the latter action further utilized to close a separate load circuit.

It will be clear that while I have disclosed the present invention is applied to three electrodes .3, '4, 5, that more than three may be utilized without departing from the true spirit of the invention.

While I have described and illustrated specific forms of the invention, it will be clear that variations thereof may be resorted to without departing from the true scope of the invention as defined in the appended claims.

What I claim and desire to secure by Letters Patent of the United States is:

.1. .In combination, a source of high frequency voltage,'a first electrode, asecond electrode, a third electrode, means for connecting said voltage and said first, second and third electrodes in series, to establish predetermined high frequency voltages between each pair of said electrodes, said electrodes separated from one another by a distance sufficiently great to prevent are over between any pair of said electrodes in response to said predetermined high frequency voltages, and means for impressing a further electrostatic voltage between an adjacent pair of said electrodes, said further electrostatic voltage suflicient in amplitude to effect are over between said adjacentpairof electrodes when superposed :on said predetermined high frequency voltages.

2. 'In combination, a sourceof high frequency voltage, an output load, a first electrode, 'a second -electrode, a third electrode, said first and second electrodes having a predetermined gap in said second and third electrodes having a predetermined gap in air, *means connecting said voltage, said load, said first electrode, said second electrode, said third electrode, all in "series, to establish a predetermined high frequency voltage between said first and second, and said 'secend and third electrodes, said gaps in air being sufficiently greatto prevent arc-over in said gaps in response to said predeterminedvoltages, an

insulator, and means for impressing a further D.-C. electrostatic voltage through said insulator across one of said gaps. said further D.-C. electrostatic voltagesufiicient in magnitude to effect arc-over in said one of said gaps when superposed on said predetermined high frequency voltages.

3. The combination 'in'accordance with claim 2 wherein said means for impressing said further .D.-C. voltage comprises, a grid controlled gaseous conduction device operated in free air as "a. gaseous atmosphere.

4. The combination in accordance'with claim 3 wherein said grid-controlled gaseous conduction devicecomprises ananode, a cathode and neontrol electrode, a voltage source, a load resistance, means connecting said anode and said cathode in series with said voltage source and said load resistance, means for deriving said 'D.-C. voltage from said resistance, and means for applying control voltage to said control electrode selectively to render said gaseous conduction device conductive and non-conductive.

5. In combination, at least three electrodes in air, a source of A.--C. voltage, means for impressing an A.'-C. voltage gradient between said at least three electrodes taken in series in response to said A.-C. voltage, said gradient lower than the gradient required to produce a disruptive discharge in air, means comprising a source of voltage for increasing the voltage gradient between only one pairof said electrodes sufiiciently to produce a disruptive discharge .in air in response to said A.-C. voltage between said one pair of said electrodes, andmeans for decoupling said source of electrostatic voltage from said source of A.-C. voltage.

6. The combination in accordance with claim 5 wherein said means for increasing the voltage gradient comprises asource of D.-C. voltage.

7. In combination, an electric circuit, circuit closuremeans for said circuit comprising at least three electrodes in air, a source of high frequency voltage of constant amplitude, means responsive to said voltage for establishing high frequency voltage gradients between said electrodes all taken in series, said gradients lower than the gradients required to produce disruptive dischargein air between any fpair of said electrodes, means comprising a source of -D.-C. voltage gradient for raising the total voltage gradient between two of said at least three electrodes to *a valuerequired to produceldisruptive discharge in air in response .to said high frequency voltage, to .said disruptive discharge completingsaid circuit through said three electrodes in series, and means for decoupling said source of D.-C. voltage from current flow in response to said high frequency voltage.

8. The combination in accordance with claim 7 wherein said circuit comprises a further main electrode and one of said first mentioned electrodes separated by air, a load, a source of voltageconnected in series with said load, said main electrode and said one of said first mentioned electrodes, and an inductance connected in serieswith'said circuit and with said at least three electrodes, to generate a voltage in said circuit sufficient to disrupt the air between said main electrode and said one of said first mentioned electrodes in response to said disruptive discharge.

9. In combination, a normally open series circuit comprising at least three electrodes in air in series in said circuit, means for applying in.

series with said series circuit a high frequency voltage of magnitude just lower than is required to produce disruptive discharge in air between any pair of said electrodes, and means for applying a further voltage between only one pair of said electrodes, and means for insulating said last means from said high frequency voltage.

10. The combination in accordance with claim 9 wherein said further voltage is a D.-C. substantially electrostatic voltage.

11. The combination of, a first electrode, a second electrode, and a third electrode, a source of high frequency voltage of predetermined amplitude, means for applying said high frequency voltage between said first and third electrodes, said second electrode having capacitive coupling with said first and third electrodes, and. assuming a predetermined high frequency potential intermediate between the potentials of said first and third electrodes by virtue of said capacitive coupling, the potential between any pair of said electrodes in response to said high frequency voltage being insufficient to cause arcing therebetween, means operative for substantially preventing current flow to said second electrode at said high frequency, and means for superposing an electrostatic control voltage through said decoupling means on the high frequency voltage between said second electrode and one of said first and third electrodes, said electrostatic control voltage of sufiicient magnitude to raise the total voltage between said second electrode and said one of said first and third electrodes above arcing potential at the frequency of said high frequency voltage.

12. The combination in accordance with claim 1 wherein is provided means for periodically interrupting said arc over.

13. The combination in accordance with claim 1 wherein is provided means for periodically reducing the amplitude of said high frequency voltage to interrupt said are over.

PIERRE MARIE GABRIEL TOULON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,074,930 Marx Mar. 23, 1937 2,408,004 Slack Sept. 24, 1946 

